Prior art nano-scale sensors are used in a large number of applications, and have been found particularly suited in the fields of chemical and/or biological sensing and analysis. Such prior art nano-scale sensors are typically produced individually by non-repetitive (and therefore inefficient) methods that do not use batch processing manufacturing techniques. Prior art nano-scale sensors find application in such analysis techniques as gas chromatography, ionically coupled plasma atomic analysis (ICPAA), wet chemical analysis, PCR (polymerase chain reaction), mass spectroscopy via laser volatilization, electrophoresis, and fluorescent tagging methods, to name a few.
Chemical and/or biological sensing and analysis traditionally requires a long time to obtain meaningful data, involves remote or cumbersome equipment, requires large sample sizes, demands highly trained users, and involves significant direct and indirect costs. Direct costs relate to the labor, procedures, and equipment required for each type of analysis. Indirect costs partially accrue from the delay time before actionable information can be obtained, e.g., in medical analyses or in the monitoring of chemical processes. Indirect costs of certain chemical or biological analyses can outweigh the direct costs.
Certain embodiments of biological and/or chemical analysis equipment use loose tubular wires or tubes whose electrical resistance is measured using a two terminal configuration. The term “loose” indicates that the wire or tube is not initially secured to the substrate and so must subsequently be affixed to it.
Advantages of the loose tube type of construction of sensors are simplicity and ease of laboratory demonstration. Minute wires can also be deposited directly on a substrate by a chemical vapor deposition (CVD) process, which is also time consuming and expensive. However, it is difficult and expensive to manufacture loose nano-scale wires or tubes in a sufficiently reproducible way for useful sensing applications.
Some analytical techniques also require arrays of sensors to sense some parameter over a two-dimensional or three-dimensional configuration. It is difficult to fabricate loose tubes or wires into arrays in large quantities, especially when the tubes or wires are in the nano-scale. Typically, each wire or tube for sensor within the array is individually fabricated, which is time consuming and expensive.
There is therefore a need for a technique for manufacturing nano-scale wires and tubes in a less expensive, more reproducible, and more production-friendly manner than permitted by present-day techniques.